Use common httpserver across fission (#2409)

* Defining httpserver package to capture httpserver shutdown and
introduces uniform running of http server across codebase.
* Add unit tests for httpserver

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

cmd/fission-bundle/main.go

@@ -200,7 +200,8 @@ Options:
 	logger := loggerfactory.GetLogger()
 	defer exitWithSync(logger)
 
-	profile.ProfileIfEnabled(logger)
+	ctx := signals.SetupSignalHandlerWithContext(logger)
+	profile.ProfileIfEnabled(ctx, logger)
 
 	version := fmt.Sprintf("Fission Bundle Version: %v", info.BuildInfo().String())
 	arguments, err := docopt.ParseArgs(usage, nil, version)
@@ -209,8 +210,6 @@ Options:
 		return
 	}
 
-	ctx := signals.SetupSignalHandlerWithContext(logger)
-
 	openTracingEnabled := tracing.TracingEnabled(logger)
 	if openTracingEnabled {
 		err = tracing.RegisterTraceExporter(logger, os.Getenv("TRACE_JAEGER_COLLECTOR_ENDPOINT"), getServiceName(arguments))